Press for producing pyrometric cones



NOV. 28.. 1939. H, 5 co VAN AL 2,181,619

PRESS FOR PRODUCING PYROMETRIC CONES Filed Dec. 16, 1935 4 3 e Ji drryz" 0 Van 6607:9814 'fiole Patented Nov. 28, 1939 UNITED STATES z smie 2,181,619 I PRESS FOR rnog pd mc PYROMETRIC Harry E. Co Van and N S George A. Bole, Columbus,

Ohio, assignors to Standard Pyrometric Cone Company, Columbus, Ohio Ohio, a corporation of Application December 16, 1935, Serial No. 54,606

Claims. I

This invention relates to improvements in pyrometric cones, a primary object thereof being to produce cones characterized by their uniform straightness, dimensional accuracy, freedom from warpage and responsiveness to definite predetermined thermal conditions.

Pyrometric cones are used in the ceramic arts primarily for the purpose of providing convenient and economical means for determining the maturity of ceramic articles when fired. Such cones comprise flat-surfaced bodies in the'general form of trihedral pyramids and possess such a composition, form and mass so that the same will weaken or soften under elevated temperature conditions. In kiln operation, when the internal temperature is sufiiciently high and the time factory long enough to cause deformation of such a cone, the operator of the kiln, by observing the physical condition of the cone, may ascertain quite accurately the maturity of the ware undergoing heat treatment. Pyrometric cones while not a substitute for thermocouples, nevertheless, constitute heat measuring devices which are quite widely used as practical guides in obtaining correct firing of ceramic bodies.

Such cones, when made in accordance with present methods of manufacture, are not characterized with that degree of uniformity by by which complete reliance can be placed by a kiln operator on their thermal deformation points. This is in the main attributable to the presently used method for producing the same, which is known in the art as the plastic method, and comprises mixing certain ceramic rawmaterials including, among others, plastic clay, feldspar, flint and whiting with anorganic binder and water until a condition approximating maximum plasticity is secured. These materials, While in a plastic state, are then shaped by means of molds into cone formation. While still in a formative or plastic state, these initially formed cones are removed from the molds by hand operation and are placed on pans or trays for delivery to a drying or baking zone, in which the cones are heated to, a temperature and for a sufiicient period of time to remove moisture therefrom and to cause their hardening into a desired state of permanency.

These operations quite commonly result in the production of cones lacking uniformity in shape and dimensions. This may be due to several causes among which are: irregularities in the pockets of the molds in which the plastic cones are formed, due to Wear or other causes; the removal of the plastic cones from the mold pockets, effected manually, for the purpose of placing the molded plastic cones on drying trays, and wherein the operator in lifting or handling the cones may cause the latter to stretch, foresh'orten or bend beyond their intended and: originally molded shapes, with the result that cones of a given class will not respond uniformly to the same thermal conditions of kiln operation, and by reason of the fact that plastic clay has a high shrinkage factor when dried through heat-, ing, and this also presents a condition which results in variation in cone dimensions. 7 It is therefore, an object of the present inven tion to produce pyrometric cones with the use of substantially dry materials through forces of- 5 compression or compaction, whereby accurately shaped and dimensioned cones maybe commercially manufactured and which will be uniformly responsive to predetermined thermal conditions.

Another object of the invention resides in providing apparatus for producing pyrometric cones with the use of substantially-dry ingredients, and wherein the apparatus comprises a press having axially aligned, relatively movable, upper and lower punch members and an associated die member having a slot formed for the movable reception of the punch members, the latter being formed with angularly related coneforming and pressing surfaces soarranged that when the punch membersare forced together, the dry cone forming materials will be subjected to uniformly applied forces of compression, securing at the same time even distribution and compaction of said materialstoproduce finished cones of uniform density throughout the length thereof and of strict dimensional accuracy.

One of the difficulties encountered in dry pressing the materials forming pyrometric cones has consisted in so distributing the materials undergoing compression as to obtain finished cones, of uniform hardnessor density throughout their length. This was apparently due to the inability of the dry materials when under compression to uniformly distribute themselves over the full length of the cone-forming pocket of the press, with the result that certain portions of the cones possessed a greater density than other portions thereof. In solving this difiiculty, the present invention provides a press in which the cone-forming pocket of one of the punch members is formed to include upper and lower longitudinal edges inclined with respect to the horizontal and in different planes, whereby when the punch members are forced together to compact the powdered materials, the latter will be adthe edges Ba.

said members when the latter are initially assembled to admit of the placing of the cone forming materials in the cone forming pocket of the press;

Fig. 3 is a similar view disclosing the upper and I lower punch members of the press in their pressing, cone-forming positions;

Fig. 4 is a similar view disclosing the punch members separated for the discharge of a formed cone from the press;

Fig. 5 is a vertical transverse sectional view taken on the line V-V of Fig. 3;

Fig. 6 is a detail view of theend plate carried by the lower punch member;

Fig. '7 is a detail view of a pyrometric cone made in accordance with the present invention.

Referring more particularly to the drawing, the numeral I designates an upper punch mem her, the numeral 2 the die block, and the numeral 3 the lower punch member. These members are adapted to be mounted in a standard form of press in substantially the arrangement disclosed. The die block 2 is formed. with a substantially Wedge-shaped slot 4 disposed in vertical registration with the axially movable punch members I and .3. In this instance, the block 2 is of circular form and has its outer peripheral edge portion provided with an annular groove 5 which is adapted for the reception of the end of a posi tioning screw 6 carried by the frame or bed of the punch press. By loosening the screw 6, the die block may be rotated so that the slot 4 provided therein may be properly registered or aligned with the punch members and 3.

In this instance, the lower of the punch members, as indicated at 3, has its upper portion formed to provide a metallic head 1 in which is formed a longitudinally extending groove or pocket 8. This groove is substantially V-shaped in vertical cross section, as disclosed in Fig. 5, the opposed inclined side walls of said pocket or groove having substantially the form of a right angle triangle. The complemental or mating surface 9 of the upper punch member is substantially flat over the .full area thereof, but is dis posed at an acute angle'with respect to the horizontal, the angularity of the surface 9 being the same as that of the upper longitudinally extending converging edges 8a of the pocket 8. The bottom centrally disposed edge .81) of the pocket 8 is also arranged at an angle with respect to the horizontal but at a greater angle than that of The angularity of the walls forming the pocket 8 and the edges 8a and 81) thereof is of material importance in enabling the dry cone-forming materials placed in said pocket and undergoing compression between the punch members to be uniformly distributed throughout the length of the pocket, so that the pressed cones resulting from the operation will .be of uniform density throughout their length.

In order to form the cone ill so that the base surface H thereof will be disposed substantially at 90 with respect to one of its side surfaces, the frame of the press, contiguous to the lower punch member, is provided with a socket for the reception of a compression spring 12. This spring is plate which has formed therein a vertical slot H for the reception of a pin l8 projecting outwardiy and laterally from the lower punch member 3.

In forming cones in accordance with the present invention, the lower punch member is adjusted vertically so that when occupying its lowermost position, the pocket 3 will be disposed within the confines of the wedge-shaped slot l of the block 2 and below the upper surface of said block. This enables the slot 5 and the pocket 8 to receive a regulated amount of the dry pow dered material, terminating evenly with the up- Der surface of the block. When this is accomplished, the upper; punch member is advanced ertically downwardly until the head thereof enters the slot 4, with the lower punch member held stationary, and until the surface it of the upper punch member contacts with the edges to of the lower punch member.

Upon the completion of the compression operation, both the lower and upper punch 12 bers are then moved upwardly, as shown i. g. 4, to facilitate the discharge of apressed cone from the machine. The lower punch member advances upwardly so that the pocket thereof will be disposed above the upper surface of the block 2 and with the upper punch member vertically spaced therefrom. This enables a cone retained in the pocket or groove to be readily accessible for either manual or automatic removal the forming region of the press. As the lower punch member moves upwardly to a cone discharging position, the spring ii at the same time elevates the plate I 4 until the enlargement it on the plate contacts with the lower surface of the die block 2. \Vhen this occurs, the upper edge of the plate I i will be disposed substantially in horizontal registration with the plane defining the top of said block so that during the entire upward movement .of the punch member, the end plate will maintain contact with the base end of the cone to prevent deformation of the latter by contact with stationary surfaces of the press. The continued upward movement of the punch member 3 following contact of the enlargement I3 with the under side of the die block is compensated for-by the provision of the elongated slot I I in the end plate in which the pin it is received, so that by the time the lower punch member reaches its extreme upward position, the pin l3 will be disposed at the upper end of the slot 11. Following removal of the pressed cone, the lower punch member and the end plate are returned to the normal positions disclosed in planeformation anddisposed at an angle with 5% by weight of the total ingredients present,

whereby to assist the action of the binder in uniting the basic materials when the same are subjected to compression. This relatively small amount of water does not sensibly affect the free flowing characteristics of the powdered materials when the latter are not under compression, nor does it render such materials in any sense plastic. Therefore, when'the expression dry powdered materials is used in the following description and claims, it will be understood that the same does not preclude the employment of a sufficient amount of water, or other equivalent liquid in connection with the binder used in the formation of the cones.

When the cones are removed from the press, they are sufficiently permanent in form so that they may be handled in the ordinary manner without deformation or loss of dimensional ac curacy. Such a cone may be used directly in the measuring of kiln heat effects or, if desired, may be subjected to heating for the'purpo-se of further drying or hardening the same.

Cones, as shown at 20, formed in accordance with the present invention, are characterized by their straight smooth side walls and freedom from distortion. Since the base surface of the cone is substantially at right angles to one of the sides of the cone, it follows that when the cone is positioned in a base, it will maintain the desired upright form and appearance. When used in a kiln, the cone by reason of its straightness, will assume a distinctive position until the materials from which it is formed are softened to a degree providing for the distortion or forward bending of the cone. At this time, the operator will be appraised of the heat condition prevailing within the kiln, thus permitting of proper and accurate thermal regulation to obtain satisfactory results in the burning or kiln treatment of ceramic articles.

One of the punch members may be provided with a removable plug, indicated at 2|, which may contain an embossed surface providing forthe formation of a number or other identifying symbol in one of the side surfaces of such cones. This is important since there are a number of cones employed for determining different heat effects and these different classes are in practice identified by numbers. The pressing of such a number in the side of a cone provides for its convenient identification.

The present invention permits the rapid manufacture of pyrometric cones of accurate dimensions and minimizes variations due to changing density of the cones. In other words, the present invention provides for the formation of pyrometric cones having more uniform characteristics in response to given thermal conditions than has been obtainable with prior methods of manufacture.

What is claimed is:

1. A press for producing pyrometic cones comprising a die having a wedge-shaped slot, coacting punch members in registration with and axially movable with respect to said slot, one of said punch members being provided with a pocket having the side walls thereof arranged in V- shaped relationship with the inner edge of the pocket formed by the merging of said side walls disposed in acute angular relationship with respect to the horizontal, and the other of said punch members having the surface thereof registering with the first-named punch member of respect to the horizontal.

2. A press for producing pyrometric cones comprising a die having a Wedge-shaped slot, relativelymovable coacting punch members disposed to register-with said slot, the meeting surfaces of said punch members being formed to provide a cone producing pocket, and additional means coacting with said punch members and disposed at one end of said pocket to cause the base ends. of a cone formed therein to lie substantially at right angles to the plane of one of the sides of thecone.

3. A press for producing pyrometric cones comprising a diehaving an opening formed therein, coacting punch members in registration with said slot and movable axially with respect to each other, the complemental surfaces of said punch members being formed to present a cone producing pocket having an open end, and means coacting with said punch members and normally closing the open end of said pocket, said means including an inclined surface in registration with the open endof said pocket by which a cone formed in said pocket will have its base end disposed substantially at right angles to one of the plane surfaces of the cone.

4. In a press for producing pyrometric cones, a die having a wedge-shaped slot formed therein,

lesser angle, the lower end of the upper of said punch members being formed to provide a pressing head shaped to conform with the configuration of said slot, the lowersurface of said head being of planar formation and possessing an incoacting punch members in registration with saida i clination with respect to the horizontal conforming with that of the upper edges of said lower punch member.

5. In a press for producing pyrometric cones, a die having a wedge-shaped slot formed therein,

coacting punch members in registration with said slot and axially movable with respect thereto, the lower of said punch members having its upper end shaped to conform to the configuration of said slot and additionally formed to provide a pocket having plane V-shaped side walls, the lower edge of said pocket formed by the merging of said side walls being inclined with respect to the horizontal, the upper longitudinal edges of said pocket, being similarly inclined but at a lesser angle, the lower end of the upper of said punch members being formed to provide a pressing head shaped to conform with the configuration of said slot, the lower surface of said head being of planar formation and possessing an inclination with respect to the horizontal conforming with 5 that of the upper edges of said lower punch member, and movable means coacting with the lower punch member and normally disposed to close the open end of the pocket formed in the lower punch member, said means being shaped to present an inclined surface to said pocket, whereby the base end of a cone formed therein will lie substantially at right; angles to one of the sides of the cone.

6. In a press for producing pyrometric cones,

a die having a-wedge-shaped slot formed therein, relatively movable upper and lower punch members having the coacting ends thereof formed to present heads, the head on the lower punch member being positioned within saidslot and conforming to the configuration thereof, the head of the lower punch member being additionally formed with a pocket having V-shaped plane side walls, the lower edge ofsaid pocket being inclined with respect to' the horizontal and the upper edges of said side walls being similarly in clined but at a lesser angle than said lower edge, the head on the upper punch memberbeing shaped to conform to said slot and to enter the latter, the lower surface of the head onsaid upper punch member being of planar formation and inclined to correspond with the inclination of the upper edges of the head of said lower punch member, a frame including a socket for the reception of said die, a plate disposed at one side of the head of the lower punch memher, a :pin and slot connection between said head and said plate, a spring arranged between the lower end of said plate and the bottom of said socket and normally tending to force said plate upwardly, the upper portion of Said plate terminating in an inclined surface normally disposed registration with the open end of said pocket, and means for limiting the sliding movement of said plate in unison with said lower punch memher.

'7. A press for producing pyrometric cones comprising a pair of relatively movable punch members having meeting surfaces inclined with respect to the horizontal, one of said members being formed with a pocket having opposed inclined side Walls of substantially triangular formation, the inner edge of said pocket formed by the joining of said side walls being inclined with respect to the horizontal but to a greater degree than the inclined meeting portions of said members.

8., In a press for producing pyrometric cones, a pair of relatively movable punch members, the complemental meeting surfaces of said punch members presenting a cone-shaped pocket having upper and lower edges inclined with respect to the horizontal, said pocket being accessible when said members are relatively separated.

9. In a press for producing pyrometric cones, a die having a wedge-shaped slot, coacting punch members axially movable with respect to each other and occupying said slot, one of said punch members including a triangular head having a longitudinal groove formed therein, said groove being provided with opposed inclined side walls each of triangular formation, the outer longitudinal edges of said groove being disposed in converging relationship and at an acute angle with respect to the horizontal, the inner edge of said groove formed by the meeting of the opposed inclined side walls being disposed at a greater angle with respect to the horizontal than the outer edges thereof, the other of said punch members being formed with a complemental head shaped to enter the Wedge-shaped slot of said die, and terminating in a planar pressing surface disposed at the same angle with respect to the horizontal as the outer longitudinal edges of said groove.

10. Pyrometric cone producing apparatus comprising a die block provided with a substantially triangular slot, a lower punch member positioned for sliding movement in said slot, said punch member being formed with a V-shaped groove in its upper surface, a spring pressed plate arranged adjacent the punch to close one end of the groove, and an upper punch member formed for sliding movement in the slot in said die block, upper punch cooperating with said lower punch and said plate to form a cone-shaped pocket.

HARRY E. CO VAN. GEORGE A. BOLE. 

